My husband & I are going round about this issue. He wants to shave Bo and I don't. I'm concerned about the potential for heat stroke/sunburn, as we live in an area of California that reaches 110 regularly during the summer. Granted, Bo can be inside or out during the day, it's still really hot. I bought some shed shampoo and good conditioner and see if that helps to get the undercoat out, which is what I think contributes to overheating.
Once the landlord at our old house had to shave their male pyr bald (I mean, BALD) due to a fly infestation (long story). They left his head unshaved, though, so he looked like a pink q-tip for weeks!! They had to put a t-shirt on him!